Clinical Trial Details
— Status: Withdrawn
Administrative data
| NCT number |
NCT02822196 |
| Other study ID # |
HSC-MS-16-0467 |
| Secondary ID |
|
| Status |
Withdrawn |
| Phase |
Phase 4
|
| First received |
|
| Last updated |
|
| Start date |
December 2018 |
| Est. completion date |
December 2019 |
Study information
| Verified date |
September 2020 |
| Source |
The University of Texas Health Science Center, Houston |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
HYPOTHESIS
Serratus Anterior Muscle Plane Block (SPB) is as effective as thoracic paravertebral block
(PVB) for acute pain control after unilateral mastectomies.
SPECIFIC AIMS
Primary aim: To evaluate the efficacy of SPB block vs thoracic PVB for acute pain control in
patients undergoing unilateral mastectomy
Secondary aim To compare the onset and duration of block and dermatomes blocked in both
groups To compare the need of post-operative rescue analgesia in both groups. To compare the
development of chronic incisional pain in both groups Functional outcome with respect to
daily activities.
Description:
RESEARCH STRATEGY
1. Background
Breast cancer is a potentially deadly disease affecting one in eight women. [1] Majority
of them undergo mastectomies along with different modalities of treatment like
chemotherapy, radiotherapy and hormonal treatments.
Since mastectomy is the main and most commonly preferred treatment for breast cancer
surgery, it raises the focus on the most frequently studied complication that is
persistent pain following surgery [8, 9] The incidence of pain syndrome six months
post-breast cancer surgical treatment was 52.9%.[7] A multivariate analysis of the
presence of chronic pain in breast cancer survivors revealed risk factors including more
invasive surgery, radiation therapy after surgery, and clinically meaningful acute
postoperative pain. Each risk factor independently predicted more intense chronic pain
at three months after surgery. [8] A 20% prevalence rate of the Post Mastectomy Pain
syndrome was found. Women experiencing the syndrome reported chronic, stable pain of
long duration that began shortly after surgery. [10] The syndrome is important to
recognize because of how debilitating the pain can be. Studies have indicated that post
mastectomy pain interferes with activities of daily living like driving, taking care of
the children, leisure time, and sex, all of which result in poor quality of life. It was
also noted that in women who survived treatment of breast cancer, chronic pain often
caused mood changes, difficulty at work, and reduction of physical activities. This was
especially noted in those women whose pain spreads to other areas of the body. [14]
There are various anesthetic techniques available for management of mastectomies. The
effectiveness of each technique is widely studied regarding pain control, requirement of
rescue analgesia, side effects, post-operative hospital stay and development of
persistent pain following breast cancer surgical treatment. Belzarena SD et al compared
the effectiveness of thoracic epidural block and general anesthesia for oncologic
mastectomy. Patients were divided in two groups in which they either received GA or
thoracic epidural anesthesia as primary anesthetic. [10] The results showed that the
quality of postoperative analgesia was better in the epidural group, which also
presented with lower consumption of analgesics. The length hospitalization in this group
was also lower. They concluded that an epidural block had some advantages when compared
with general anesthesia and can be considered an anesthesia option in oncologic
mastectomies with axillary lymph node dissection.
Newer regional anesthesia techniques have been developed to improve pain control and
patient satisfaction. These includes epidural blocks (thoracic and cervical), single
injection thoracic PVB and intercostal nerve blocks. PVB during breast cancer surgery
have been reported to decrease acute pain and opioid consumption immediately following
surgery in multiple randomized clinical trials [4, 5, 6] and were superior over epidural
blocks due to lower complication rate. A thoracic PVB is a well-established anesthetic
technique and has been proven to be safe for mastectomies.
The most recent advancement in anesthetic techniques for mastectomies is the SPB. The
SPB is a novel technique first described by Fajardo et al in 2012 [2]. A single
injection blocks many dermatomes at once. This technique could be an effective
alternative to PVB or thoracic epidurals, because it is considered more feasible, safe
than thoracic epidurals and results in a lower complication rate. But there are very few
long term randomized studies to prove the efficacy of SPB.
R. Blanco et al studied this novel ultrasound-guided regional anesthetic technique to
provide analgesia following surgery on the thoracic wall in four volunteers. All
volunteers reported an effective block that provided long-lasting paresthesia (750-840
min). There were no side-effects noted in this initial descriptive study. They have
suggested to confirm these preliminary results in a large clinical trial.[12] Currently
only a single major clinical trial comparing the effectiveness of SPB and PVB for Breast
Cancer Resections is being conducted by Ghada M N Bashandy, National Cancer Institute,
Egypt. [13]
2. Protocol/Experimental Design/Flowchart/Primary and Secondary End Points
Criteria
Ages Eligible for Study: 18 Years to 80 Years Genders Eligible for Study: Female No. of
subjects in each group: 50. (Total = 100)
Informed consent for the procedure will be taken. Patients will be educated on the use
of the visual analogue scale (VAS) to evaluate their pain level and a printed copy of
the VAS scoring will be provided to take home. After the completion of preoperative
assessment by the OR nurse, the patients will be randomized to either SPB group or PVB
group. The block will be performed pre operatively. To reduce patient anxiety and
improve comfort, midazolam 0.02mg/kg IV will be given except in patients > 70 years of
age. Standard ASA monitors were applied including pulse oximetry, noninvasive blood
pressure, and electrocardiogram.
Procedure: Serratus Anterior Muscle Plane block (SPB)
The US probe will be placed in the mid-axillary line at the level of the 5th intercostal
space. The latissimus dorsi (superficial and posterior), teres major (superior) and
serratus muscles (deep and inferior) will be identified. Using in-plane approach, the
block needle (22 G, 50 mm) will be inserted until the tip is visualized between the
serratus anterior muscle and the intercostal muscles. As an extra reference point
thoracodorsal artery will be used which aids in the identification of the plane
superficial to the serratus muscle. After negative aspiration of blood, local anesthetic
(20 ml of 0.25 % bupivacaine) will be injected and visualized in real-time. [11]
Procedure: Paravertebral Block (PVB)
Patients will be placed in the sitting position, leaning forward. After skin
disinfection using chlorhexidine solution, target spinous processes of T1- T5 will be
identified and at parasagittal plan at 2.5 cm, skin wheel will be raised using 1%
lidocaine. A 20-gauge, bevel needle will be advanced until the transverse process is
located. The depth from skin to transverse process will be marked/identified by needle
marking. The needle will be withdrawn 1-2 cm and angled down (walked off the transverse
process). The needle will be re-advanced 1cm past the initial marking. After negative
aspiration, 4-5 ml of 0.25% bupivacaine will be slowly injected. The same procedure will
be repeated at each level from T2 to T6 ensuring total dose of bupivacaine does not
exceed the maximum dose recommended. [13]
After the block is performed, all subjects will receive induction of general anesthesia
with fentanyl 1-2 mcg/kg, propofol 1-2 mg/kg and suxamethonium 1 mg/kg. After induction
the trachea will be intubated with 7.0 mm ID endotracheal tube. For analgesia all
patients will receive 1 gm of intravenous acetaminophen. Anesthesia will be maintained
with sevoflurane with oxygen and air. To minimize PONV, every patient will receive
ondansetron 4mg at the end of the surgery. Fentanyl 25 mcg boluses will be used as
rescue analgesia intra operatively. When extubation criteria have been met the trachea
will be extubated and the patient will be taken to PACU.
PACU phase I For VAS >6, 0.5 mg intravenous hydromorphone every 10 min up to 2 mg as a
rescue analgesia For VAS
PACU phase II Prior to discharge all patients will receive tramadol 50mg if they have
not required pain medication in phase I.
At discharge, all patients will be prescribed Norco (7.5/325) every 4 hours prn for
VAS>4.
Reinforcement of previous education on VAS scoring will be done as part of discharge
instructions by the discharge nurse.
The following parameters will be recorded in each group.
- Duration of block analgesia - time to peak of pain/return of sensation after
surgery will be recorded
- Dermatomal distribution of sensory loss obtained after block tested with ice.
- Assessment of static and dynamic VAS scores at 0 (on arrival to PACU), 6, 12, 24
and 48 hours, 3 months and 6 months after surgery and additional set of questions
to assess neuropathic pain. ( painDETECT)
- Time for 1st rescue analgesia
- Total dose of rescue analgesia received during the first 24 and 48 hrs
3. Sample size and statistical analysis
Statistical analysis plan StatistiCall will create the randomization list by using the
software ClinStat (from St. George's Hospital Medical School, Version dated 08.05.96). The
treatment will be named 1 for SPB Block, 2 for PVB block for both parts of the study in the
list. Block randomization in X blocks of X patients will be used.
Since there is no valid data comparing the 2 blocks, we are unable to construct a realistic
power analysis as the hypothesis of difference between the 2 procedures are potentially
minimal and not yet statistically proven. Therefore, this initial investigation in 100
subjects is clinically and logistically feasible and analysis will provide statistical
guidance to any necessary additional studies.
The investigators will be responsible for analyzing the study data, and the analysts will be
blinded to patients' group assignment during the execution of the study. For the purpose of
the final analysis, the official clinical database will not be unblinded until
medical/scientific review has been completed and the investigators have been assured that the
data are complete.
Before performing any analysis, the distribution of all variables will be examined for
appropriateness of distribution assumptions. Descriptive statistics will be summarized for
all variables including demographics, duration of analgesia, VAS scores during rest and after
surgery, time for 1st rescue analgesia, total dose of rescue analgesia received in 24 hrs and
side effects. Mean ± SD will be reported for continuous variables and frequency (percentage)
will be reported for discrete variables. Analysis of variance or Kruskal-Wallis test as
appropriate will be used to analyze and compare the primary endpoint VAS among two groups as
well as the secondary endpoints. Chi-square test or extended Fisher's exact test as
appropriate will be used for the comparison of the incidence of chronic pain as well as other
side effects. All analyses will be performed using SAS 9.3 (Cary, NC) and a p-value less than
0.05 will be considered as statistically significant.
